Picking a volunteer vacation is a lot like dating: The choices are mind-boggling, but finding the right fit takes work. Treat the search like a job.

Opportunities to travel and immerse yourself in a different culture are everywhere. You can enlist through religious organizations, schools and alumni associations, museums and charities. Pick an activity, a location and a time frame, then determine your budget. Comb the Internet, ask questions of organizers — and yourself.

Do you mind sharing a bathroom? Do bunk beds cause sleepless nights? Can you live without Internet?

These questions are being answered and acted on in large part by baby boomers who are experienced travelers and advocates of this type of travel experience. They have free time, disposable income and gypsy fever from college years.

Boomers are using vacations to track elephants in Kenya with Earthwatch, build homes around the world with Habitat for Humanity, repair trails in Colorado and Patagonia, and restore lighthouses along Lake Superior. They're teaching English in Eastern Europe and assisting as nonmedical volunteers on Mercy Ships, the floating hospitals that cruise West Africa to provide care to locals.

Flexibility and realistic expectations are critical.

"No one is going to change the world in one week," insisted Doug Cutchins, a co-editor of "Volunteer Vacations" (Chicago Review Press), a comprehensive resource of 140 volunteer programs. The opportunities are organized by activity, location, cost, duration, even seasons. "If you insist on immediate, measurable outcomes, think twice. Development, especially in Third World countries, is hard work and depends on long-term engagement. It's a process, including failure."

So why go? Because there is a payoff for those who do. I'll start with the service vacation I took in March to Guatemala.

Solar systems and salsa: Last year Next Step Travel, a department of the National Peace Corps Association, introduced volunteer vacations to Guatemala and the Dominican Republic. The association is a kind of alumni organization in the Peace Corps community. At the time, Edith Ury already was doing research when she came across Next Step's 10-day trip to Guatemala, which focused on community and educational projects. It fit her availability, curiosity and budget ($2,199, excluding airfare to Guatemala City). "I'd never been to Central America, and I love to travel. But my husband doesn't," explained the Montreal psychotherapist, who at 77 is above the boomer threshold.

The same trip also appealed to me and others. Our group of 12 ranged in age from 44 to 77. Ten of us were former Peace Corps volunteers who had served at various times since the 1960s, though service in the corps is not a requirement. We settled into a small hotel, where all meals were provided and helped out each morning at an elementary school near Quetzaltenango.

Once our work was done, afternoon excursions took us to historic villages with cobblestone streets, a weaving workshop, a coffee plantation and a dip in hot springs. Guest speakers also schooled us on the culture. Salsa lessons were a hit.

Lesson plans in Lima: Barbara Cherem, 66, celebrated her retirement last year from the University of Michigan at Flint by signing up for a volunteer vacation in Peru. After weeks of Internet research, the Ann Arbor resident chose Global Volunteers of St. Paul., Minn., to teach English and current affairs at La Molina National Agrarian University in Lima.

"The novelty of travel — new sites, souvenirs, photos — wears off with age. What's gratifying is using my teaching skills to learn a culture, firsthand, from its people," she said. "I loved the enthusiasm and caliber of my students. ... I was tired but exhilarated." Cherem paid all expenses, including the program fee of $2,595 for the two-week assignment.

Tapas and talkathons: Shirley Termaat considers Spain a second home.

"I've made so many friends through volunteering," explained the 62-year-old banking executive from Delray Beach, Fla. She's a four-time veteran of VaughanTown, a volunteer program that connects native English speakers with Spanish professionals in structured, conversation-focused sessions.

The intensive six-day program is at one of four locations outside Madrid. Volunteers and students stay in hotels and residences and spend as long as 11 hours daily conversing in English — over meals, in business-related role-play activities, in seminars on culture and on walks.

Volunteers apply online and, if accepted, supply round-trip airfare to and from Madrid. Food, lodging and in-country transportation are provided by Vaughan Systems, a Madrid-based company founded by American-born Richard Vaughan. It contracts year-round English training to major corporations in Spain.

She encouraged friend Joe Hollenkamp, 67, of Chicago to join also. At first he thought it too good to be true. But he went, and "when it was over, I was beat. I needed a vacation — and got it in Barcelona.''

Family matters: The baby boomers who traversed Europe in the 1960s and '70s on shoestring budgets now are taking their kids and grandkids along, according to Cutchins of "Volunteer Vacations.". Anna Phillips, group programs director of Pittsburgh-based Amizade Global Service-Learning, helped the Fein family of Scottsdale, Ariz., find a placement in Poland.

Jeff Fein and wife Jill, both 51, agreed with their two children to experience, firsthand, their Jewish heritage, learn about the Holocaust and see where some of their relatives came from. The Feins' 10-day service trip to concentration camps near Krakow followed studies on Jewish history by Jackson, 16, and Ginger, 14.

Work days at Auschwitz-Birkenau included doing grounds maintenance and monument repair at cemeteries and helping with office work in the museum's archives. Evening debriefings with the group leader, a professor from Germany, enabled the family to review the day's experiences, and amend, if necessary, the next day's agenda.

"It was a powerful, emotional experience," Jill added, "not always easy. But we talked it through. It changed us, and yes, we'd do it again."